Freezing apparatus for making ice blocks



Oct. 30, 1956 c. HOEN 2,768,507 FREEZING APPARATUS FOR MAKING ICE BLOCKS Filed Sept. 50, 1953 2 Sheets-Sheet 1 nvunwwe Cale/V220 H05 c. HOEN 2,768,507

FREEZING APPARATUS FOR MAKING ICE BLOCKS Oct. 30, 1956 2 Sheets-Sheet 2 Filed Sept. 30, 1953 WIHMHHMMHNIM m 1 i i j w m wwwwwww E United States Patent FREEZING APPARATUS FOR MAKING ICE BLOCKS Cornelis Hoen, Vught, Netherlands, assignor to Grassos Machinefabrieken N. V., s-Hertogenbosch, Netherlands, a company of the Netherlands Application September 30, 1956, Serial No. 383,223

Claims priority, application Netherlands October 7, 1952 9 Claims. (Cl. 62-4069 The invention relates to apparatus for producing ice in blocks or cakes, in which one or more ice cells, mounted upright and unmovable, are provided with cooling jackets (vide e. g. British patent specification No. 622,415).

The application of direct evaporation within a cooling jacket of the ice cell involves the necessity of mounting the ice cell unmovable i. e. stationary within the frame of the apparatus, in contrast with earlier ice generators, in which the cells were lowered into a brine tank and after the freezing of their contents were lifted out in their entirety in order to be thawed and emptied.

When an ice cell is unmovable, it will also have to be thawed to free the ice block, and to be discharged on the spot. In known machines this discharge is effected in the downward direction, i. e. by means of the weight of the block of ice itself. This necessitates the provision of a releasable closing device at the underside of the ice cells. This closing device (cover) tends to complicate matters. It has to seal the ice cell hermetically during its filling with water. To achieve this it is preferably first frozen to the cell, but in this way the risk is incurred that during the filling of the ice cell the closing device may thaw off again, causing the ice cell to be emptied of its contents again. The removal of the cover after the complete freezing of the block of ice also involves difliculties, and finally it is a complicated business to blow air into the contents of the cell through the movable cover, which blowing in of air is desirable in order to obtain clear ice.

The invention obviates the above-mentioned drawbacks.

According to the invention, one or more ice cells in a freezing apparatus as referred to is closed only at the upper end and is freely open at the lower end in a water tank, beneath the liquid level, and said cell is provided with an air suction pipe and, if necessary, an air release pipe and/or a gas or liquid delivery pipe connected to the upper end.

The mechanical closing device is replaced as it were by a liquid seal. The ice cell is filled from the same tank in which already pre-cooled water is present, by suction with the aid of the air suction pipe. Thus, no special filling devices are required. The water tank has a limited size. It does not surround the water jackets of the ice cells, which thus do not require any special insulation, and on the outside of which no ice can therefore be deposited, which would involve the risk of the cells bursting.

Built-in ice cells are known for making comparatively small blocks of ice in the form of hollow bars, according to the Fechner system (vide Pohlmann, Taschenbuch fiir Kaltetechniker, 12. Aufl., page 262, or Netherlands Patent No. 39,620). These ice cells also end in a water tank, even at both ends, and they are therefore open at both ends. In these machines the water circulates through the cell, which would involve too long a ice freezing period for large blocks of ice. Moreover the machine would then become too big, and the jackets would be difficult to insulate and in sutficiently accessible.

It is to be noted that in the previously known brinecooled ice generator mentioned in the opening paragraphs the ice cells were also closed at one (narrow) end and open at the other (wide) end, without any closing devices, but with the first-mentioned end at the bottom. These ice cells were not built in and there was no communication between the water in the cell and the liquid (brine) outside.

The drawing illustrates an embodiment of direct evaporation freezing apparatus according to the invention.

Fig. l is a vertical cross-section through an ice cell of a machine with one row of ice cells.

Fig. 2 is a diagrammatic side elevation of the conveying system for the blocks of ice in a machine according to Fig. 1.

Figures 3 and 4 show some details of modified embodiments.

In Fig. l the numeral 1 designates an ice cell which is closed at the upper side, open at the underside, widening slightly towards the open end, and mounted so as to be integral with or at least stationary within the machine. The open end reaches down into a tank 2 to beneath the liquid level 3 in the latter. This tank 2 is kept filled with pure water, suitable to be frozen into blocks of ice, for example with the aid of a pump 4 with a valve 5 controlled by a float 6. Thus the level 3 of the liquid is kept constant.

At the top of the ice cell 1 enters a suction pipe 7, which is connected to a vacuum chamber 8. This vacuurn chamber 8 is connected at one side to an air suction pump 9, and is provided at the other side with a valve 10, by means of which an accurately adjustable vacuum can be created in the chamber 8. When a valve 11 in the pipe is opened, the ice cell 1 is emptied, with the result that water is sucked from the tank 2 into the ice cell 1 to the level 12, the height of which can be accurately regulated through the adjustment of the vacuum.

In this way the ice cell is easily and very quickly filled with the water to be frozen.

The ice cell is surrounded by a hollow jacket 15, in which direct evaporation of a refrigerant may take place. Along the centre line there also extends in the ice cell from the top downwards a tubular space 16, in which direct evaporation of a refrigerant may also take place, so that the block of ice is frozen from two sides (outside and inside) and is thus rapidly formed.

The refrigerating system operates in the following manner: A compressor 17 is provided with a suction pipe 18 and a delivery pipe 19. The latter leads to a condenser 20, whence the liquefied refrigerant flows through a pipe 21 to a coil 22 in a separator 23 and to a throttle valve 25 which might, if necessary, be operated by a float acting on the level of the liquid in the separator 23. In the valve 25, throttling andpressure reduction take place, after which the liquid refrigerant flows through a pipe 26 deep into the tubular space 16, which constitutes a central cooling channel. The pipe 26, which has a smaller diameter than the channel 16, enters concentrically into the latter and continues to within a short distance of the closed lower end of the channel 16. The liquid refigerant flows out of the open lower end of the pipe 26, and rises in the channel 16, while partly evaporating and thus absorbing heat from the liquid to be frozen which surrounds the channel 16.

Via a pipe 29, which is connected to the channel 16, the mixture of vapour and liquid enters the separator 23. Here the vapour is separated off and sucked away via I'he separator 23 communicates via pipes27 and 28 with thejacket 1'5, softhatJthe liquid refrigerant can continuously flow' via the pipe .27 to 'this jacketfwhere it is partially evaporated, absorbing heatwm from the liquid to be frozen. frigerant and vapour rises very rapidly in the jacket 15, and via the pipe '28 reaches the separator 23 again, where the vapouri's'sucked away, while the liquid refrigerant separating off there re-enters the cycle described.

The refrigerant is pre-cooled .in the coil 22.

When ablock of ice has been formed, it has to be thawed off the walls. This is achieved by admitting vaporous, compressed, hot refrigerant into the jacket and also into'the centralicooling channel 16. This is done in'the following manner:

A valve 30 in the suction pipe 18 is'closed, and a valve 31 is opened, as a result of which the pressure side of the compressor '17is connected via a pipe 32 to the separatcr'23; The liquid refrigerant, which is present in the jacket 15 and in the central cooling channel 16, is forced out via the pipes"28 and 29; From the jacket it flows otf through the pipe 27 into a tank 33, with condensation of the gaseous refrigerant present therein. From the central cooling channel 16 the refrigerant flows off through the pipe 26, and via a valve 36, which is The mixture of liquid re open, toa pipe 24' and thus on to the tank 33. The valve has meanwhile been closed.

When the block of ice has thawed oif sufficiently, it can move down from the ice cell 1, provided the space above it is filled up with air. This discharge of the block of ice may be accelerated by compressing the air in the ice cell above the block. This can be done in the following The air suction pump 9forces air into an air chamber 40, which is provided with a valve 41, by means of which an accurately adjustable air pressure can be maintained' in the chamber 40. The valve 11 is closed, and

perpendicularly beneath the ice cell 1. During'the freez-' ing process, air bubbles may by this means be caused to.

rise in the ice cell 1, as a'resultof which clear ice is produced.-- This air has to be continuously sucked away through the pipe 7, the vacuum, however, having to be accurately maintained.

When the block of ice is expelled, it sinks vertically down in the tank 2. Provisions are then made to ensure that, according to Fig. 2," beneath-the ice cell being discharged, there is a receiving device 50,'into which enters This receiving device is equipped the blockof ice 51.

with a pawl or other gripping-device-52; whichprevents' the block of ice rising to the top again. The receiving device 50 may be attached to rods 53 of a lifting crane, by means of which the block-'of ice 51 can now "easily 'be removed from the tank -2.

It is obvious that the water in the tank 2 will be cooled,

which would fall beyond the reach of the thawing action in the jacket 15 and in the central cooling channel 16. The cold developed in the jacket 15 must therefore be prevented from proceeding as far as the mouth of the ice cell, and consequently a heat insulation 49 has been provided, which might effectively be replaced by a heating jacket.

When the block of ice drops'into the tank 2, it has a central channel in the place where the central cooling channel 16 passed throughit. In the tank 2 this channel wiil at once he filled with water, and since the block ofice was supercooled, this water will freeze fairly rapidly, the more so because it is filled with already precooled water. In this way a solid block of ice is formed.

In Hg. 3 the ice cell l'according to Fig. 1 with its accessories is again illustrated. The same reference numbers designate identical parts. The ice cell 1 is provided with a pipe 60, connected to a tank 61.. This tank reaches with a standpipe 62 to beneath the level 3 in the tank 2. In the tank 61 there is a float 63 operating a float valve 64. This float valve controls the suction pipe I, which is now directly connected to the air suction pump 9.

When the water sucked up in the ice cell 1 reaches the level 12, it also reaches this level in the tank 61. At that moment the float 63 has risen so far as to close the valve 64, so that the suction is arrested. This float valve regulation therefore takes the place of the vacuum control valve 16 in Fig. l. The arrangement is simpler than that in Fig. 1. The tanks 8 and 40, and also the valves 10 and 41, may be omitted.

Fig. 4 shows another embodiment of the same detail, which, if anything, is simpler still. In this case the pipe 7 extends at once throughthe closed upper-side of the ice cell 1 inwards to the lever 12. The pipe 7 is connected to the suction side of a self-priming centrifugal pump 70. The pump 70 operates continuously, but it is obvious that the water level in the cell 1 cannot rise above the level 12. During the freezing-process an upward flow is maintained in the cell 1, which is favourable for the pre-cooling of the water in the tank 2 and also for the clearness of the ice to be produced. Air may also be blown in. Measures should, however, be taken to prevent the ice from adhering by freezing to the mouth of the pipe 7;

What I claim is:

1. Apparatus for making ice blocks 'from a liquid, comprising a tank for said liquid,'means maintaining said liquid in said tank at a fixed level, an ice cell having side walls conforming in shape to said block and having a closed top and an open bottom; means'mounting said cell in fixed position above said tank with the lower ends of said side walls'extending below said fixed liquid level to dip into said liquid and form a liquid seal for the lower open'end of said cell but being spaced above the bottom of said tank to provide clearance for the removal of said ice blocks after said blocks have been discharged into said tank from the open lower end of said cell, a coolingjacket' to receive a' vaporizable refrigerant surrounding said side walls above said liquid level, and suction means connected to the closed top of because during the freezing process thereis constant circulation of the waterbetween theice cells and the-tank 2. It is naturally advantageous that the ice cell 1 is filled each time with this already considerably pre-cooledwater.

It is naturally also possible to provide-an evaporator. coil in the tank 2, sothat the water'in this tank maybe cooled to nearly0 CL, thus reducing the: heat the pipe 16.

Care has to be taken to ensure that the freezing process shall. not extend sofar to the openmouth of the ice cell .1: as "to; cause the formation of ice at this mouth,"

said cell for causing the liquid to be-drawn upwardly into said cellfor freezing:

2. Apparatus according to claim 1; wherein the ice cell is tapered, with the narrowend at the top and the wide end at the bottom.

3. Apparatus according to claim 1, wherein the liquid level inside the ice cell is controlled by a float valve which controls the suction means.

4. Apparatus according to claim 1, whereinthe suction means comprises a pipe connected to the suction side of a'self-primingcentrifugalliquid pump and extending into the ice cell to the levelto'which the liquid is to be drawn.

5. Apparatus accordingto claim" 1," characterized in that an air nozzle is provided in the tank beneath the open lower end of the ice cell.

6. Apparatus according to claim 1, wherein there is provided in the tank, beneath the open lower end of the ice cell, a receiving device for the block of ice to be discharged downwardly from the ice cell, said receiving device being equipped with a gripping device which prevents the block of ice from again rising to the top of the liquid.

7. Apparatus according to claim 1, characterized in that a central cooling channel extends downwardly into the ice cell from the closed upper end.

8. In an apparatus as set forth in claim 1, means applying air pressure to said top of said cell to assist in removing the ice block therefrom.

9. Apparatus as set forth in claim 1, including means supplying a heating medium to said jacket for melting the ice block therefrom.

References Cited in the file of this patent UNITED STATES PATENTS Riker May 29, Hemphill Aug. 25, Corbett Apr. 6, Wussow Oct. 18, Bayston Nov. 20, Ploeger Sept. 30, Lauer Mar. 31, Lee Aug. 18, Wilbushewich Nov. 15,

FOREIGN PATENTS Italy Dec. 17, Germany May 4, Great Britain Dec. 5, Germany July 21, 

